Offset boring head



W. N. MILES OFFSET BORING HEAD Dec. 1, 1964 2 Sheets-Sheet 1 Filed Feb. 8, 1963 m, m m

, WILBUR N. MILES WromnavezV DeC- 1 1964 w. N. MILES 3,159,060

OFFSET BORING HEAD Filed Feb. 8, 1963 2 Sheets-Sheet 2 ","f |4 W 20h f FIG? f 2\\ as r2a 7 FIGA FIG. 6

42 INVENTOR.

WILBUR N. MILES ATTORNEY United States Patent C 3,159,060 OFFSET BORING HEAD Wilbur N. Miles, Chagrin Falls, Ohio, assiguor to Erickson Tool Company, Solon, Ohio, a corporation of Ohio Filed Feb. s, 1963, ser. 257,238 9 Claims. (Cl. 77-58) This invention relates as indicated to an offset boring head and more particularly to a micrometrically adjustable offset boring head. j

Offset boring heads are commonly used in machine tool practice where a high degree of precision is required for both the sizing and location of the bored holes, the increments of adjustment often being in the range of 0.0001 of an inch or less.

It is a primary object of the present invention to provide an offset boring head of improved, highly simplied, construction capable of extremely precise adjustment, i.e. to about .0001 of an inch. A corollary object is to provide an improved offset boring head which is compact, lightweight, and which canbe economically manufactured. p

Another object of the invention is to provide an offset boring head having a readily accessible adjusting mechanism having easily viewed indicia permitting accurate and precise adjustment of the tool holding member relative to the shank.

Another object of the invention is to provide a novel locking assembly for locking the tool holding member in its precisely adjusted position.

Other objects and advantages of the present inven tion will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features here? inafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail Icertain illustrative enibodirnents of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. l is a perspective View on a reduced scale of the offset boring head forming the present invention;

FIG. 2 is an exploded perspective view showing the offset boring head in disassembled form;

FIG. 3 is an axial sectional View through the boring head on line 3-3 of FIG. 4;

FIG. 4 is an axial sectional View through the boring head taken on line 4 4 of FIG. 3;

FIG. 5 is an end elevational View of the boring head, with certain structure being omitted for reason of clarity, taken from the right of FIG. 4;

FIG. 6 is a sectional view taken on line 6-6 of FIG. 5; and

FIG. 7 is a sectional view taken on line 7--7 of FIG. 4.

Referring now to the drawings, and particularly to FIG. l, the offset boring head of the invention is generally indicated at 10 and comprises a main body or housing 11 having a shank 12 attached thereto, the shank being adapted for mounting in a spindle or similar part of a machine tool for rotation thereby. A tool holding slide member 13 is mounted for adjustment Within the main body 11 as will be described below and carries a suitable cutting tool T as shown in dashed lines. `An adjusting dial 14 is rotatably mounted on the housing 11 and has indicia 15 formed therein at the end thereof adjacent that portion of the main body 11 containing similar indicia 16, rotation of dial 14 thus effecting precise radial adjustment of the tool holding slide member 13. A cap member 17 is disposed in abutment with the 3,159,060 Patented Dec. 1., 1964 ICC opposite end of dial 14, the cap 17 being mounted to the housing 11 as will be described hereinbelow, whereby said dial 14V is rotatably but axially stationary relative to said main body 11. A hand knob 18 which forms part of a locking assembly extends outwardly from the housing 11 for locking the slide 13 in its adjusted position. Rotation of the dial 14 is effective to vary the radial distance between the axes of the shank 12 and the axis of the cutting tool T whereby the latter can be precisely radially adjusted to permit holes of varying sizes to be accurately bored in a workpiece.

Referring now to a more detailed description of the components parts of the boring head, and primarily to FIG. 2, the main body 11 is provided with threads 19 at one end thereof for threadedly receiving the shank 12. The main body 11 further comprises four separate, circumferentially spaced, arcuately shaped members 20 (FIG. 7), the curved outer portions 21 thereof being on a smaller radius than the radius of that portion of the main body 11 containing the indicia 16. The members 20 define a pair of perpendieularly disposed slots 22 and 23, the purpose of such slots being further described hereinbelow.

The graduated dial 14 is adapted to be telescoped over the arcuate members 20, one end of the dial being provided with an annular flange 24 for mounting the dial 14 in close abutting relationship with a complementary flanged portion of the main body 11 adjacent the indicia 16. The dial 14 is interiorly threaded as indicated at 2S and exteriorly knurled as shown at 26 to facilitate rotation thereof.

The tool holding member or slide 13 is telescoped Y within the dial 14 and is slidable in slot 23 formed in the housing 11 in a direction transverse to the axis of said dial 14. Movement of the slide Vmember 13 is effected by means of a slide actuating pin 27 which is threaded at opposite ends thereof as shown at 28 for threaded engagement with the threaded interior 25 of the dial 14. The actuating pin 27 is provided intermediate the ends thereof with oppositely disposed parallel flats 29 for positioning the actuator in an obliquely directed slot 30 in the block portion 31 of the slide 13. As will be further described below, rotation of the dial 14 will, through movement of the pin 27, effect movement of the slide 13 in a direction transverse to the axis of the shank 12 thus varying the radial setting of the tool T relative to the shank axis. The slide 13 is provided with a forward end portion 32 which is axially and transversely bored for receiving a suitable cutting tool, such cutting tool being held in position by means of a set screw adapted -to be threadedly disposed in a threaded opening 33 formed in such forward end portion. A pair of shoulders 34 are formed on opposite sides of the block portion 31 of the slide 13 for permitting the slide to be locked in its adjusted position by means to be hereinafter described.

The cap member 17 is provided with an annular flange 35 adapted to engage a complementary flange on the adjacent end of the dial 14 thereby to maintain the dial in an axially stationary position on the main housing, cap screws 36 Ibeing provided which extend through openings 37 in the cap 17 and into tapped openings in the portions 20 of the mainhousing for maintaining the dial in such assembled position. Y The cap 17 is formed with an elongated opening 38 for Vaccommodating radial movement ofthe slide 13.

The locking assembly previously referred to comprises, in addition to the hand knob 18, a pair of locking pins 40 slidable in openings in two di-agonally disposed arcuate members 20a and 2Gb of the housing 11, noting FIG. 7, and extend parallel to the longitudinal axis of the housing. As will be more clearly seen below when particular reference is made to FIGS. and 6, a pair of diverging locking pin actuators 39 are disposed in the housing 11. The locking pin actuators 39 are beveled at one end thereof for engagement with correspondingly beveled end portions of the locking pins 40. A slotted and threaded bushing 41 is slip fitted in an opening 43 in the housing 11,

vthe bushing being retained in such position by means of a conepoint pin 42. The locking pin actuators 39 are simultaneously movable by means `of knob 18 through a wedge 44 in a manner to be described hereinbelow, such movement causing movement of th'e locking pins 40 axially relative to the housing 11 into engagement with the shoulders 34 of slide 13 for locking the slide in an adjusted position. Such movement :of the knob 18 also effects a pressing ofthe bottom of the conepoint pin 42 against the flange of the dial 14 whereby said dial is also effectively locked in position.

Referring now to the manner in which the cutting tool T is radially adjusted, relative to the axis of the shank 12, the knob 18 is loosened to unlock the dial 14 and to free the ends of the locking pins 40 from rm contact with the shoulders 34 of the slide 13, thereby unlocking the latter for radial ,adjustment upon rotation of the dial 14. The dial 14 is then rotated in the desired direction, such rotation being indicated by the scale or indicia 15 on the dial. The indicia 16 formed in the main housing 11 yfunction as a Vernier scale whereby the unit of adjustment of the indicia 1S can be more precisely determined by `'such Vernier scale 16, in the well-known manner of Vernier adjustment. Radial movement of the slide 13 responsive to rotation of the dial 14 is effected through movement of the slide actuator 27 in a direction parallel to the llongitudinal axis of the dial 14, the latter being axially stationarily mounted on the housing, .as above described. Movement of the slide actuator 27 in the slide slot 30 causes the slide 13 to be moved in a direction transverse to the axis 'ofthe dial 14. When the slide 13 has been radi-ally moved the amount desired as indicated by the indicia reading on the di-al, the knob 18 is rotated clockwise to lock the slide in its adjusted position. Re-

kferring to FIGS. 5 and 6, the clockwise movement of the hand knob will effect movement of the locking .pin actuators 39 and the locking pins 40 as above described, the pins 40 moving in an axial direction relative to they main body 11 and the slide 13 until the end portions of the pins 40 `firmly contact the shoulders 34 of the slide 13 whereby the slide 13 is clamped between the pins 40 and the ca-p 17. The dial 14 is also lockedjin position responsive to clockwise movement of the knob 18, also as above described. It should be noted that the force applied to the slide 13 during the locking thereof is in a direction perpendicular to the movement of the slide 13 in its range of adjust-ment, whereby there 4is no tendency for the locking assembly to throw'the slide 13 out of its adjusted position or to affect the dial setting. Y

The boring head of the present invention is capable of highly'precise adjustment. By employing a cylindrical dial calibrated in thousandths of an inch, accuracy of adjustment, by reason of .the Vernier scale, may be within .0001 of an inch. For example, when the threads 25 and 28 are of 20 pitch, `one revolution of lthe dial will advance the actuator .050 in an axial direction `and when the angle of slot 30 is 26 -34, the slide 13 will move radially .025 per revolution of dial 14. Accordingly 50 divisions around dial 14 will indicate .050 change in diameter or .001" per division and the Vernier scale will enable change in diameter within .0001".

It will accordingly be seen that the present invention provides an offset boring head which is compact and highly simplified in construction, yand which is capable of achieving highly 'precise adjustment. The. cutting tool can be easily and quickly locked in its radially adjusted position. Further, the design of ythe boring head is such as to seal vthe same from the entrance of dust and foreign matter.

Q ther modes of applying the principle of the invention `may be employed, change 'being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

l therefore particularly point out and distinctly claim as my invention: y

1. An adjustable boring head comprising a main body portion, tool holding means, pin actuating means disposed in an opening in said tool holding means for moving said tool holding means in a direction transverse to the longitudinal axis of said main body, indicia-bearing dial means threadedly connected to said pin actuating means, rotation of said dial means effecting movement of said .pin actuating means in a direction parallel tothe axes of said dial means and said'main body portion, said pin actuating means thereby moving said tool holding means in a direction transverse to said longitudinal axis of said main body to vary the radial distance yfrom said longitudinal axis to the axis of said tool holding means, and means for locking said tool holding means in an :adjusted position.

2. The combination of-claim 1 including `means for locking said dial means in adjusted position.

3. The combination of claim l wherein said means for locking said tool holding means in an adjusted position includes at least one locking pin slidable in an opening in said main body portion extending in a direction parallel to the longitudinal axis thereof, and means for effecting movement of said locking pin axially relative to said main body portion into frictional locking engagement with said tool holding means.

4. The combination of claim 3 wherein there are two of said locking pins slidable in longitudinally extending openings in said main body portion, and said means for causing movement 'of said locking pins comprises a pair of diverging locking pin Aactuators disposed in said main body portion, the radial inner ends of which are beveled for engagement with correspondingly beveled end portions on said locking pins, and wedge means for simultaneously moving said'locking pin actuators into engagement with said locking pins to cause axial movement thereof as aforesaid.

5. The combination of claim 2 wherein said means for locking said tool'holding means and said dial means in an`V adjusted position comprises a pair of'locking pins slidable in longitudinally extending openings in said main body portion, a pair of diverging locking pin actuators disposed in said main body portion, the radial inner ends of which are beveled for engagement with correspondingly beveled end portions on said locking pins, an opening in said main body portion into which the radial outer ends of said locking pin actuators extend, a bushing sliptted into said opening and having a slot for receipt of said radial outer .ends of said locking pin actuators, said bushing being retained in position by means of a conepoint pin, the opposite end of which is disposed adjacent one end of said dial means, a wedge disposed in said slot engaging said locating pin actuators, and a screw means threadedly .engaging an aperture in said bushing and extending into said slot, whereupon tightening of said screw means causes simultaneous movement of said locking pin actuators through said Wedge into engagement with said locking pins to cause movement of said locking pins relative to said main body portion into locking engagement with said tool holding means, such movement of said locking pin actuators also causing a slight outward movement of said bushing to force the opposite end of said conepoint pin into locking engagement with said dial means.

6. An adjustable boring head comprising a main body portion, a tool holding slide having a slot therein obliquely directed relative to the longitudinal axis thereof, pin actuating means movably disposed in said slot in said tool holding slide for moving said slide in a direction transverse to the longitudinal axis of said main body portion, and indicia-,bearing dial means threadedly connected to said pin actuating means, whereby rotation of said dial means effects movement of said pin actuating means in a direction paraliel to the axes of said dial means and said main body, said pin actuating means thereby moving said slide member in a direction transverse to the longitudinal axis of said main body to vary the radial distance from said longitudinal axis to the axis of said ytool holding slide.

7. The combination of claim 6 wherein said dial means is cylindrical and rotatably mounted on said main body portion and coaxial therewith, said main body portion being provided with a Vernier scale opposite indicia on said dial means to permit precise adjustment of said dial means and said tool holding means, and further including means for maintaining said dial means coaxial with and axially stationary relative to said main body portion, said last-mentioned means comprising a cap mounted on said main body portion, said cap being provided witha central opening to accommodate all positions of adjustment of said tool holding means.

8. The combination of claim 6 wherein said main body portion comprises four separate circumferentially spaced members which define a pair of perpendicularly disposed slots, said tool holding means being slidable in one of said slots in such transverse direction, and said actuating means being slidable in the other of said slots in such axial direction.

9. An offset boring head comprising a main body adapted to receive a shank for mounting said boring head on a machine tool, toolholding means slidably mounted in said main body in a. direction transverse to the axis of said shank for radially adjusting said tool holding means relative thereto, actuating means mounted in an opening in said tool holding means for moving said tool holding means in such transverse direction, said opening yin said tool holding means being obliquely directed relative to the axes of said shank and said main body whereby movement of said actuating means in said opening is greater than the radial movement of said tool holding means, and cylindrical dial means mounted on said main body for moving said actuating means in a direction parallel to the axes of said shank and said main body, said dial means being axially stationarily mounted on said main body, and said actuating means comprising a pin threadedly engaging said dial means and axially movable relative thereto.

References Cited in the le of this patent UNITED STATES PATENTS 2,090,718 Young Aug. 24, 1937 2,333,233 Bold Nov. 2, 1943 2,507,286 Trocki May 2, 1950 FOREIGN PATENTS 590,098 Great Britain Iuly 8, 1947 

1. AN ADJUSTABLE BORING HEAD COMPRISING A MAIN BODY PORTION, TOOL HOLDING MEANS, PIN ACTUATING MEANS DISPOSED IN AN OPENING IN SAID TOOL HOLDING MEANS FOR MOVING SAID TOOL HOLDING MEANS IN A DIRECTION TRANSVERSE TO THE LONGITUDINAL AXIS OF SAID MAIN BODY, INDICIA-BEARING DIAL MEANS THREADEDLY CONNECTED TO SAID PIN ACTUATING MEANS, ROTATION OF SAID DIAL MEANS EFFECTING MOVEMENT OF SAID PIN ACTUATING MEANS IN A DIRECTION PARALLEL TO THE AXES OF SAID DIAL MEANS AND SAID MAIN BODY PORTION, SAID PIN ACTUATING MEANS THEREBY MOVING SAID TOOL HOLDING MEANS IN A DIRECTION TRANSVERSE TO SAID LONGITUDINAL AXIS OF SAID MAIN BODY 